Since a seat pad used for seats and chairs provided on vehicles such as cars, ships, and aircrafts is demanded to have a cushioning property as well as a vibration absorbing property, synthetic resin flexible foam such as flexible urethane foam is used. However, since the flexible foam has a low air permeability, sweat coming from a person who takes a seat is prone to cause a sweaty feeling. Therefore, there is a technique in which a recess that communicates with a vent hole is formed on the front surface of a pad main body made of flexible foam, a three-dimensional mesh-like body in the same dimensions as the dimensions of the recess is fit into the recess, and a seat pad is manufactured (Patent Literature 1). In the technique disclosed in Patent Literature 1, the three-dimensional mesh-like body is formed of a plurality of three-dimensionally entangled fibers, so that the air permeability of the seat pad in the thickness direction is secured using the three-dimensional mesh-like body and the vent hole, and a sweaty feeling experienced by a person who takes a seat can be suppressed.